DE3325688A1 - Switch - Google Patents

Abstract

A switch has a housing (21), a push-button element (10), a contact element and contact pins (31, 32). The push-button element (10) can move the contact element into a plurality of switch positions in which the contact element produces or interrupts an electrical connection between the contact pins (31, 32). In this case, the contact element is a multi-layer spiral spring (20), and, in the switch position corresponding to an electrical connection, the contact pins (31, 32) engage in the space between two adjacent turns of the spiral spring (20) (Fig. 1). <IMAGE>

Description

Applicant; Stuttgart, July 6th, 1983

ddm hopt + schuler GmbH & Go.KG. P 4397 Heerstrasse 44

7210 Rottweil

Representative;

Kohler - Schwindling - Späth
Patent attorneys
Hohentwielstrasse 4-1

7000 Stuttgart 1

counter

The invention is based on a switch with a housing, a pushbutton element, a contact element and contact pins, in which the contact element can be brought into several switching positions by the pushbutton element, in which the contact element establishes or interrupts an electrical connection between the contact pins.

Such switches are known as pushbutton switches, slide switches, toggle switches or the like. The contact element at these known switches can for example consist of a one- or two-part contact spring, which is in the Position in which the electrical connection between two or more contact pins is made, resiliently this pushes several contact pins.

The known arrangements with the leaf spring-like contact element however, have the disadvantage that the contact force is not high enough in all cases and that they in particular does not remain constant over longer periods of time. Known switches of this type are also not sufficient always meeting today's requirements for reliable contact, even with long actuation intervals and shock loads.

The invention is therefore based on the object of improving a switch of the type mentioned at the outset to the effect that that despite the small structural dimensions, high contact forces occur, which even with long-term use, guarantee reliable contact with long actuation intervals and shock loads.

This object is achieved according to the invention in that the contact element is a multi-layer spiral spring and that the contact pins in the switch position corresponding to an electrical connection in the space between engage two adjacent turns of the spiral spring.

The contact spring designed as a spiral spring with at least more than one completely closed turn is accordingly When the contact pins penetrate, it opens in the axial direction and thereby generates a high contact pressure or a high contact pressure on the contact pins. By the load on the spiral in the axial direction results in a high contact pressure in a small space, so that even with Miniature switches ensure high contact reliability in the event of shock loads and can be guaranteed when actuated after a long time in the same switch position.

In a preferred embodiment of the invention, the spiral spring consists of round material. This measure has the advantage that self-centering is achieved when shifting in the longitudinal direction and when closing the switch, this centering takes place both with regard to the position and with regard to the forces that arise.

Another embodiment is preferred in which the Contact pins lie in one plane and the spiral spring with the area spanned by it in or parallel is deflected to this plane. This measure allows a design with a particularly low depth dimension.

Depending on the position of the contact pins, the spiral spring can be deflected in different movement paths. however, an embodiment is preferred in which it is deflected linearly. This way you can be preferred Push and slide switches can be set up.

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In one embodiment of the switch according to the invention the contact pins are designed as flat tongues, which preferably terminate in cutting edges at their free ends. This embodiment has the advantage that a particularly large contact surface is created because the adjacent turns the spiral spring serving as a contact element on both sides of the tongues along a circumferential segment rest, so that a flat contact is created. In addition, in this exemplary embodiment, too, there is a particularly flat design and the mechanical switching resistance is due to the cutting edges at the free ends of the Tongues particularly low.

In a further embodiment of the invention, the contact pins have a rectangular cross section and each point with an edge to each other. This measure has the advantage that mechanically particularly stable contact pins are available, which can work together with coil springs for particularly high contact requirements, which over have a particularly high rigidity.

The contact pins are preferably rectangular Cross-section provided at its free end with a pyramid-shaped tip to mechanize the switching resistor to reduce.

Finally, in a further embodiment of a switch according to the invention, the contact pins are provided to be provided with a circular cross-section and preferably a cone at the free end of the contact pins to be provided. This measure has particular advantages in terms of production technology, because the contact area is circular in cross section.

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pens are particularly easy to work with and look special suitable for switches that are soldered directly onto printed circuit boards. Another benefit of this circular contact pins is that the absence of any sharp edges, especially with simultaneous Using a spiral spring made of round material leads to particularly low wear without self-cleaning to reduce the contact elements.

When using contact pins with a rectangular or circular cross-section, it is possible according to the invention by suitable choice of the center distance of the contact pins on the one hand and the diameter of the spiral spring on the other hand, to set a different number of contact points.

Thus, the diameter of the spiral spring can preferably be greater than or equal to the minimum center distance of the Contact pins are adjusted, then results in a contact point on each side of each contact pin.

If, on the other hand, the diameter of the spiral spring is larger than the center distance of the contact pins, the result is two contact points on each side of each contact pin.

In this way it is possible, depending on the requirements on the contact force, a smaller or a larger number of contact points with a correspondingly lower or higher actuation force of the switch.

By bending over the contact pins once or several times, it is also preferably possible to obtain a smaller one or to set a larger number of contact points.

In order to define the various switch positions by means of detent positions of the mechanically moving parts of the switch, In one embodiment of the invention, the shape of the contact pins can be chosen so that the contact pins themselves define these locking positions in cooperation with the spiral spring. These locking positions can, for example, preferably by notches or beads on the contact pins getting produced·

This measure has the particular advantage that the switch housing can then be constructed in a particularly simple manner, because further locking elements are not required.

In another embodiment of the invention, however, it is provided that the locking positions by interaction of the Produce tactile element with the housing surrounding it. Locking lugs and notches are preferably used, which are each arranged on the housing or on the pushbutton element, or vice versa. This measure has the advantage that as Contact pins simple profiles can be used.

Finally, the fixing of the spiral spring can be more advantageous when the switch according to the invention is actuated Wise caused by the fact that the spiral spring of two protruding from a wall of the probe element Projections is held, between which a web of the

Housing extends so that the spiral spring is fixed in the axial direction of the wall and the web. Through this simple structural measure ensures that the contact pins are always at a defined circumferential point the spiral spring come into engagement with this because a lateral migration of the spiral spring is not possible.

Further advantages emerge from the description and the attached drawing.

The invention is shown in the drawing and is explained in more detail in the following description. Show it:

Fig. 1a to 1c an exploded view of an embodiment

Approximate form of a switch according to the invention, partly in section;

2 shows an embodiment of a switch according to the invention with contact tongues;

Fig. 3 shows an embodiment of a switch according to the invention with rectangular Contact pins;

4 shows an embodiment of a switch according to the invention with cylindrical contact pins and a small diameter coil spring;

FIG. 5 shows a representation corresponding to FIG. 4, but with a spiral spring of a larger one Diameter

6 shows an embodiment of an inventive

Moderate switch with locking positions defined by the contact pins;

Pig. 7 shows a modification of an embodiment according to Pig. 6th

Pig. 8 shows a further modification of an embodiment according to Pig. 6th

Pig. 9 shows an embodiment of a switch according to the invention with bent contact pins to increase the number of contact points

Pig. 10 shows a modification of an exemplary embodiment

according to Pig. 9.

In Pig. 1, 10 is a touch element which is provided with a touch surface 11 on its upper side. On a back wall 18 of the probe element 10 guide flanges 12 are formed laterally. In the area opposite the wall 18 are on the probe element 10 elastic arms 13, 14-, preferably in one piece, formed, which at their free end with locking notches 15, 16 are provided. At the bottom, from the Touch surface 11 facing away from the end of the wall 18 emerge at right angles from these two projections 1? from, which are close together, however, they are arranged with a finite space between them.

A multi-layer spiral spring 20 is pushed onto these projections 17, the projections 17 being dimensioned in this way are that they fill the free interior of the spiral spring 20 almost completely.

The pushbutton element 10 with the inserted multi-layer spiral spring 20 is pushed into a housing 21 from above. The housing 21 has a rear wall 22, which is adjacent to the guide grooves 23, 24 in which the guide flanges 12 of the probe element 10 run. In the opposite area of the housing 21 there are guide surfaces at right angles to one another 25 is provided, on which the elastic arms 13, 14 run. In one guide surface 25 there are locking lugs 26, 27, which define two switch positions of the switch in the embodiment according to FIG. 1, if, for example, the locking notch 16 cooperates with the locking lug 26 and with the locking lug 27 on the other hand.

On a front wall 28 is a vertical direction extending web 29 is formed, the width of which is dimensioned so that the web 29 in the space between the projections 17 can run · In the assembled state of the switch, the axial position of the spiral spring 20 is thus once fixed by the rear wall 22 and the other by the web 29.

Finally, contact pins 31, 32, likewise in a vertical direction, are arranged in a base 30 of the housing 21, and they terminate in a cone 33 at their free end.

As can be seen from Fig. 1 without further notice, is located the spiral spring 20 is in the upper switching position of the switch, in which the locking notch 16 with the locking lug 26 cooperates, at a distance from the contact pins 31, 32, so that the electrical contact between these contact pins 31 »32 is interrupted. If the pushbutton element 10 is now pushed into the housing 21 by pressing the pushbutton surface 11 pressed in, the switch reaches the other detent position, in which the locking notch 16 cooperates with the locking lug 27. Me free ends of the contact pins 31, 32 within of the housing 21 now slide with their cone 33 into a lateral area of the spiral spring 20 between two adjacent turns, because the spiral spring 20 due to the fixation by the projections 17, the rear wall 22 and the web 29 can not evade.

As a result of the penetration of the contact pins 31, 32, the spiral spring 20 is widened in the axial direction and the two Coils of the spiral spring 20 which are pressed apart and lying next to each other come into contact under high pressure to the contact pins 31, 32 on both sides.

In the embodiment of FIG. 1 and also in the further exemplary embodiments, which are described in detail below, are provided for the sake of simplicity only assumed a switch in which the electrical contact between two stationary contact pins is closed or interrupted. It is understood, however, that more complicated switching functions with several

Helical springs and several switch positions built up can be, for example, by placing a helical spring successively in contact or out of contact along its path Contact can come to a plurality of contact pins, which, according to the desired rating, are received in a suitable Way are wired. In this way, 'for example slide switches with a variety of Build switch positions.

The invention is in no way limited to a linear working path of the helical spring 20, Rather, this can also be swiveled in the plane spanned by it! or be swiveled out of this plane, as long as contact pins come into engagement between the turns of the spiral spring according to the invention.

In the embodiment according to FIG. 2, two tongue-shaped contact pins 40, 41 are used, their free ends merge into cutting edges 42, 43. The one engaged with both Contact pins 40, 41 illustrated coil spring 44, as from the plan view in Pig. 2b particularly clearly visible is expanded axially, so that a considerable contact pressure P arises in the contact area. Making contact in the embodiment according to FIG. 2 takes place along a ring segment-shaped line on both sides of the contact pins 40, 41. This creates a large Transition surface between the pins 40, 41 and the spiral spring 44, which this embodiment is for high switching currents makes suitable. However, the force that is required to move the spiral spring 44 is also

Speaking greater, because the friction between the spiral spring and the pins 40, 41 is also greater.

The embodiment according to FIG. 3 differs from that according to FIG. 2 initially in that contact pins 50, 51 with a rectangular cross-section, which is square in the illustrated embodiment, are used, wherein the squares stand on the point in the view according to FIG. 3b. The contact pins. 50, 51 are at theirs the free end is provided with a pyramidal tip 55. If a coil spring 52 is now engaged from above with the Pins 50, 51 brought, the spiral spring 52 of the mutually facing edges 53, 54 of the pins 50, 51, or their continuations in the area of the pyramidal tip 55 'widened, so that again a high contact force P occurs.

Another difference to the previously described embodiment However, there is still the fact that the diameter d, j of the spiral spring 52 is smaller than the axial spacing d £ of the contact pins 50, 51 ». As a consequence, that in the contact area the spiral spring 52 in each case one Point rests on corresponding inclined surfaces of the contact pins 50, 51, so a total of four contact points. Thus, although the effective transition area is smaller than in the embodiment described above, the necessary to move the coil spring 52. However, the force is also correspondingly lower.

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In the embodiment according to Pig. 4- contact pins 60, 61 with a circular cross-section are used, as well as this was the case in the embodiment according to FIG. The contact pins 60, 61 are also at the free end provided with a cone *

The diameter d, of the spiral spring 62 is in turn smaller than the center distance d ^, of the contact pins 6O ₁ 61, so that also in the embodiment according to FIG. 4 in terms of geometry, contact conditions corresponding to the embodiment according to FIG .

In contrast, the effective contact area is in the exemplary embodiment according to FIG. 5 twice as high. Contact pins 70, 71, which are circular in cross section used with a coil spring 72. The diameter d, - the However, coil spring 72 is in this embodiment greater than the center distance dg of the contact pins 70, 71, so that two contact points are formed on both sides of the contact pins 70, 71, for a total of eight contact points. This doubles the number of contact points compared to the exemplary embodiments in FIGS. 3 and 4, However, this also means the force required to move the spiral spring 72, because of the greater force that now exists Friction.

It goes without saying in this context that the contact quality in addition to the considerations explained above, of course, also by the rigidity of the respective

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used spiral spring can be influenced. In addition, the contact quality is influenced by the geometry the arrangement used, for example in the exemplary embodiments 3 and 4 by the ratio of the spring diameter and distance and in the embodiments according to FIGS. 4- and 5 by the diameter of the Contact pins.

The exemplary embodiments according to FIGS. 6, 7 and 8 illustrate different ways of locking the switch through the contact pins themselves define.

In the exemplary embodiment according to FIG. 6, two contact pins 80, 81 which are circular in cross section are different Length used. The contact pin 80 is provided with notches 82, 83 provided, the notch 83 corresponding to a notch 84 at the same height at the contact pin 81. In one switch position, which corresponds to an electrical connection between the two contact pins 80, 81, there is a spiral spring 85 in engagement with notches 83, 84. In the other Switching position, which is indicated with 85a, is located the spiral spring 85, however, only in contact with a contact pin 80, so that the connection between the two Contact pins 80, 81 is interrupted.

From the embodiment according to FIG. 6 one can clearly see how a slide switch with more could be constructed as two locking positions, namely in such a way that the pin 80 with further locking positions is extended upwards and in the axis of the pin 81

above the switching position indicated by 85a another pin connects.

In the embodiment according to FIG. 7, cylindrical contact pins 90, 91 are also used, the end sections of which 93 »94, however, facing each other, bent over are. In the lower switching position, the spiral spring 82 is in engagement with both contact pins 90, 91, If the spiral spring 92 is now deflected upwards into a position designated 92a, the lower end slides of the coil spring 92 from the end sections 93, 94, so that the coil spring 92 is out of contact with the contact pins 90, 91 device. As a result, the electrical connection between the contact pins 90, 91 is interrupted and on the other hand, a mechanical locking position is defined.

A third variant, in which the locking positions are formed by the contact pins themselves, is shown in FIG. 8. This variant largely corresponds to that according to FIG. 6, because it is also cylindrical contact pins 100, 101 are used, but on which beads 102, 103, 104 are arranged instead of notches. The bulges 102, 104 on both contact pins 100, 101 define, together with a spiral spring IO5, a lower switch position, while the second bead 103 arranged on the contact pin 100 ensures that in the upper switching position 105a, the spiral spring 105 has a sufficient distance from the other contact pin 101.

This embodiment could also be for a multi-position switch can be continued upwards at will.

The exemplary embodiments according to FIGS. 9 and 10 illustrate finally, a correspondingly higher number of contact points, such as by bending over the contact pins can be achieved.

In the exemplary embodiment according to FIG. 9, cylindrical contact pins 110, 111 are provided, the end sections of which 112, 113 are bent towards one another at an angle. In the drawn Position a coil spring 114 is therefore at two points on both sides of the contact pins 110, 111, as has already been explained in the exemplary embodiment according to FIG. 5. In the difference however, the diameter of the spiral spring 114 · is in relation to this less than. the center distance of the contact pins 110, 111 in the not yet bent area. This embodiment thus has the advantage that, despite the use of a relatively small helical spring, contact is made with ins-r a total of eight contact points is made possible.

The same applies to the exemplary embodiment according to FIG. 10, in which two contact pins 120, 121 also have circular cross-section can be used, the arcuate first bent towards each other and then away from each other are. A spiral spring 124, the diameter of which is in turn smaller than the center distance of the contact pins 120, 121 in the area that has not yet been bent over is also in contact in the position shown in FIG. 10 a total of eight contact points, because through the mutually facing central areas 122, 123 the contact pins 120, 121 in the plan view the spiral spring 124 each, because cut it twice. Even with this design example

Therefore, despite the use of a relatively small helical spring, contact is made with a total of eight contact points possible.

It goes without saying that the numerous variants described above can also be used in other combinations or in each case can only be used according to the invention by using individual features.

Claims (21)

Claims Λ J switch with a housing (21), a pushbutton element (10), a contact element and contact pins (31, 32; 40, 41; 50, 51; 60, 61; 70, 71; 80, 81; 90, 91; 100 , 101; 110, 111; 120, 121), in which the contact element can be brought into several switching positions by the pushbutton element (10) in which the contact element establishes an electrical connection between the contact pins (31, 32; 40, 41; 50, 51 ; 60, 61; 70, 71; 80, 81; 90, 91; 100, 1o1; 110, 111; 120, 121) produces or interrupts, characterized in that the contact element is a multi-layer spiral spring (2o, 44, 63, 72, 85, 92, 105, 114-, 124-) and that the contact pins (31, 32; 40, 4-1; 50, 51; 60, 61; 70, 71; 80, 81; 90, 91; 100, 1o1; 110, 111; 120, 121) engage in the switch position corresponding to an electrical connection in the space between two adjacent turns of the spiral spring (20, 44, 63, 72, 85, 92, 105, 114, 124) . 2. Switch according to claim 1, characterized in that the spiral spring (20, 44, 63, 72, 85, 92, 105, 114, 124) consists of round material. 3. Switch according to claim 1 or 2, characterized in that that the contact st if te (31, 32; 40, 41; 50, 51; 60, 61; 70, 71; 80, 81; 90, 91; 100, 101; 110, 111; 120, 121) lie in one plane and that the spiral spring (20, 44, 63, 72, 85, 92, 105, 114, 124) with the is deflected by its spanned surface in or parallel to the plane. 4 ·. Switch according to one of Claims 1 to 3, characterized in that that the spiral spring (20, 44, 63, 72, 85, 92, 105, 114-, 124 ·) is linearly deflected. 5. Switch according to one of Claims 1 to 4, characterized in that that the contact pins (40, 4-1) are designed as flat tongues. 6. Switch according to claim 5, characterized in that the tongues at their free end in cutting edges (4-2, 4-3) leak. 7. Switch according to one of claims 1 to 4-, characterized in that that the contact pins (50, 51) have a rectangular cross-section and each with an edge (53 * 54-) facing each other. 8. Switch according to claim 7 »characterized in that the contact pins (50, 51) terminate at their free end in a pyramidal tip (55). 9. Switch according to one of claims 1 to 4, characterized in that that the contact pins (31, 32; 60, 61; 70, 71; 80, 81; 90, 91; 100, 101; 110, 111; 120, 121) have a circular cross-section. 10. Switch according to claim 9 _S, characterized in that the contact pins (31, 32; 60, 61 ;, 70, 71; 80, 81; 90, 91; 100, 1o1; 110, 111; 120, 121) in a cone (33) expire. _ 3 - 11. Switch according to one of claims 7 to 10, characterized in that the diameter of the spiral spring (72, 114, 124) greater than or equal to the minimum center distance of the contact pins (70, 71; 110, 111; 120, 121) is such that on both "sides each Contact pin (70, 71; "110, 111; 120, 121) two contact points with the spiral spring (72, 114, 124) occur. 12. Switch according to claim 11, characterized in that the contact pins (110, 111) are bent towards one another and that the diameter of the spiral spring (114) is smaller than the center distance of the non-bent sections of the contact pins (110, 111), but larger than the clear width between the free ends (112, 113) of the contact pins (110, 111). 13. Switch according to claim 12, characterized in that the contact pins (120, 121) arc on one another towards and towards their free ends are bent away from one another again and that the diameter of the spiral spring (124) smaller than the center distance of the non-bent sections of the contact pins (120, 121) and smaller than the distance between the free ends, but greater than the clear width at the point of closest approach Contact pins (120, 121) is. 14. Switch according to one of claims 7 to 13, characterized in that the diameter of the spiral spring (52, 62, 85, 105) smaller than or equal to the minimum center distance of the contact pins (50, 51; 60, 61; 80, 81; 100, 101) is such that on both sides Each contact pin (50, 51; 60, 61; 80, 81; 100, 101) has a contact point with the spiral spring (52, 62, 85, 105) occurs. 15 · Switch according to one of claims 7 to 13, characterized in that that the diameter of the spiral spring (92) is less than or equal to the minimum center distance the contact pins (90, 91) and these are bent over with their free ends pointing towards one another, such that a contact point with the spiral spring (92) occurs on both sides of each contact pin (90, 91). 16. Switch according to one of claims 1 to 15, characterized in that that the switching positions (85a, 92a, 105a) by locking elements (82, 83, 84; 92, 93; 102, 103, 104) the contact pins (80, 81; 90, 91; 100, 101) are defined, which cooperate with the spiral spring (85, 92, 105). 17. Switch according to claim 16, characterized in that the locking elements have notches (82, 83, 84) or beads (102, 103, 104) of the contact pins (80, 81; 100, 101). 18. Switch according to claim 16, characterized in that the locking elements by bent end portions (93, 94) of the contact pins (90, 91) are formed, which in one switching position (92a) the engagement area leave the spiral spring (92). 19. Switch according to one of claims 1 to 15, characterized characterized in that the switching positions are defined by locking elements (26, 27) of the housing (21), _ 5 - those with corresponding locking elements (15 »16) of the probe element (10) work together. 20. Switch according to claim 19, characterized in that the latching elements are designed as latching lugs (26, 27) in the housing (21), which with corresponding, on elastic Arms (13, 14-) of the feeler element (10) arranged locking notches (15, 16) work together. 21. Switch according to one of claims 1 to 20, characterized in that that the spiral spring (20) of two protruding from a wall (18) of the probe element (10) Projections (17) is held, between which a web (29) of the housing (21) runs, so that the spiral spring (20) is fixed in the axial direction of the wall (18) and the web (29).